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41.
Reactive oxygen species (ROS) cause oxidative stress by generating reactive aldehydes known as 4-hydroxynonenal (4-HNE). 4-HNE modifies protein via covalent adduction; however, little is known about the degradation mechanism of 4-HNE-adducted proteins. Autophagy is a dynamic process that maintains cellular homeostasis by removing damaged organelles and proteins. In this study, we determined the role of a superoxide dismutase (SOD) mimetic MnTnBuOE-2-PyP5+ (MnP, BMX-001) on rotenone-induced 4-HNE aggresome degradation in HL-1 cardiomyocytes. A rotenone treatment (500 nM) given for 24 h demonstrated both increased ROS and 4-HNE aggresome accumulation in HL-1 cardiomyocytes. In addition, cardiomyocytes treated with rotenone displayed an increase in the autophagy marker LC3-II, as shown by immunoblotting and immunofluorescence. A pre-treatment with MnP (20 µM) for 24 h attenuated rotenone-induced ROS formation. An MnP pre-treatment showed decreased 4-HNE aggresomes and LC3-II formation. A rotenone-induced increase in autophagosomes was attenuated by a pre-treatment with MnP, as shown by fluorescent-tagged LC3 (tfLC3). Rotenone increased tubulin hyperacetylation through the ROS-mediated pathway, which was attenuated by MnP. The disruption of autophagy caused HL-1 cell death because a 3-methyladenine inhibitor of autophagosomes caused reduced cell death. Yet, rapamycin, an inducer of autophagy, increased cell death. These results indicated that a pre-treatment with MnP decreased rotenone-induced 4-HNE aggresomes by enhancing the degradation process.  相似文献   
42.
This paper explores the potential of reducing the annual energy consumption of a central air-conditioned building through advanced evaporative cooling systems. The building considered is a typical three floor library building of a University. The regenerative evaporative cooling technology is coupled with the liquid cooled water chiller system to accomplish the energy conservation objective. Comparisons of the regenerative evaporative cooling are made with simple evaporative cooling to bring out the importance such a system. The well-known building simulation software, TRNSYS is used to carry out the heat load calculations and the dynamic simulations of the building. Annual energy consumptions of different components of the air-conditioning system are estimated for the existing water chiller system as well as for both coupled evaporative cooling systems (simple and regenerative). The annual energy consumptions, the indoor temperature, the relative humidity and the thermal comfort index ‘PMV’ are compared for all the three different air-conditioning systems. The coupling of direct and regenerative evaporative cooling technologies with water chiller system has shown, respectively, 12.09% and 15.69% savings in annual energy consumption of the building, while maintaining PMV between ?1 and +1 for most of the hours in the year.  相似文献   
43.
The impact of the Prehospital Trauma Life Support (PHTLS) programme, introduced in Trinidad and Tobago in 1992, was assessed by questionnaires completed by 26 medical personnel (MP); 71 ambulance personnel (AP); and 50 non ambulance paramedical personnel (NAP). Of the 23 MP, 45 AP and 38 NAP who were aware of the programme, 19 (82.6%) MP, 40 (88.9%) AP and 25 (65.8%) NAP were able to differentiate personnel that had taken the PHTLS programme based on their performance. 32 (71.1%) of the AP were PHTLS trained. 24 (53.3%) and 4 (9%) of the AP identified poor equipment and poor supervision, respectively, as reasons for difficulty in applying PHTLS principles. Improvements observed among those completing the PHTLS programme were: improved resuscitation techniques by 20 (86.9%) MP, 38 (84.4%) AP and 27 (71.1%) NAP; better vital signs recording by 8 (34.8%) MP, 27 (60%) AP and 8 (21.1%) NAP; improved immobilization by 23 (100%) MP, 40 (88.9%) AP and 33 (86.8%) NAP; better haemorrhage control by 22 (95.6%) MP, 40 (88.9%) AP and 24 (63.2%) NAP; appropriate splinting of fractures by 23 (100%) MP, 40 (88.9%) AP and 32 (84.2%) NAP; and increased utilization of oxygen by 15 (65.2%) MP, 31 (68.9%) AP and 21 (55.3%) NAP. 32 (71.1%) AP with PHTLS training indicated improvement in their ability to resuscitate and transport trauma victims, with 42 (93.3%) reporting improvement in overall prehospital care. Medical, paramedical and ambulance personnel all perceive a significant positive impact of PHTLS training on prehospital trauma care. Although improvements in supervision, documentation and equipment are still required, improved trauma resuscitative techniques after PHTLS training should improve trauma patient outcome in Trinidad and Tobago.  相似文献   
44.
This study reports on the effect of the addition of Glycine to Hank's solution on the in-vitro corrosion behavior of AZ31 magnesium (Mg) alloy at 37 ℃ and a pH of 7.4 studied by using potentiodynamic polarization (PDP),hydrogen collecting techniques and electrochemical impedance spectroscopy (EIS) in combination with surface characterization techniques such as optical microscopy (OM),scanning electron microscopy(SEM),energy dispersive spectroscopy (EDS),X-ray diffraction (XRD) and X-ray photoelectron spectroscopy analysis (XPS).The results reveal that adsorption of glycine initially subdues the dissolution ofAZ31 Mg alloy while in long run it enhances the dissolution of the alloy due to the commencement of the chelation effect ofglycine with Ca2+ released from hydroxyapatite.The chelation ofglycine with Ca2+induces the formation of cracks in the surface film which further promotes the dissolution ofAZ31 Mg alloy thereby forming a porous corrosion products layer on the surface of the alloy.As a result,both the continuous dissolution of AZ31 magnesium alloy and the hydrogen evolution rate (HER) are enhanced with increasing the immersion time in Hank's solution.  相似文献   
45.
Photonic crystals (PC) are of great importance in technology, especially in optics and photonics. In general, the structural color of PCs responds to external stimuli primarily by changing their periodicity. Herein, the authors report on refractive index (RI) adaptive PCs. Cross-linked cholesteric films with interconnected nanopores exhibit a very low RI without light scattering. Transparent PC films with maximum reflectance in the ultravoilet (UV) region respond to various chemicals by changing the reflective color of the PC. The authors demonstrate its unique colorimetric chemical detections of hazardous organic liquids. Loading various chemicals into nanopores significantly shifts the structural color into the visible range depending on the chemical's RI. These results are unique in that the structural color of photonic films is mediated by RI changes rather than periodicity changes. In principle, nanoporous photonic crystal films can detect the RI of a chemical substance by its unique color. In contrast to volumetric changes, this sensing mechanism offers several advantages, including durability, excellent sensitivity, fast response time, and wide detection range. These results provide useful insight into stimulus-responsive PCs. The structural color of PC films can be effectively tuned by adjusting average RIs instead of changing periodicity.  相似文献   
46.
Simplified analysis systems that offer the performance of benchtop instruments but the convenience of portability are highly desirable. We have developed novel, miniature devices that feature visual inspection readout of a target's concentration from a ~1 μL volume of solution introduced into a microfluidic channel. Microchannels are constructed within an elastomeric material, and channel surfaces are coated with receptors to the target. When a solution is flowed into the channel, the target cross-links multiple receptors on the surface, resulting in constriction of the first few millimeters of the channel and stopping of flow. Quantitation is performed by measuring the distance traveled by the target solution in the channel before flow stops. A key advantage of our approach is that quantitation is accomplished by simple visual inspection of the channel, without the need for complex detection instrumentation. We have tested these devices using the model system of biotin as a receptor and streptavidin as the target. We have also characterized three factors that influence flow distance: solution viscosity, device thickness, and channel height. We found that solution capillary flow distance scales with the negative logarithm of target concentration and have detected streptavidin concentrations as low as 1 ng/mL. Finally, we have identified and evaluated a plausible mechanism wherein time-dependent channel constriction in the first few millimeters leads to concentration-dependent flow distances. Their simplicity coupled with performance makes these "flow valve" systems especially attractive for a host of analysis applications.  相似文献   
47.
We have performed atomistic molecular dynamics (MD) simulations of water molecules inside narrow, open-ended carbon nanotubes placed in a bath of water molecules. The radius of the tube is such that only a single file of water molecules is allowed inside the tube. The confined water molecules are shown to be positionally ordered even at a temperature of 300 K. The calculated mean-square displacement (MSD) of the confined water molecules reveals that initially the water molecules undergo ballistic motion that crosses over to normal (Fickian) diffusion at longer times. We also develop a random-walk model in 1D for the motion of a cluster of water molecules inside the nanotube. The agreement of the MSD calculated from the MD simulation and from the 1 D random-walk model establishes the occurrence of normal diffusion of water molecules even in a tube where single-file diffusion is expected.  相似文献   
48.
The aim of this study was to identify the types of gallinacin genes (GALs) expressed in ovarian follicles and to determine the changes in their expression during follicular growth and in response to lipopolysaccharide (LPS). Follicles at different stages of growth were collected from laying hens (n = 5) and LPS-injected hens (n = 3). The expression of GALs in the theca and granulosa layers was examined by semi-quantitative RT-PCR. The expression of GAL-1, -2, -7, -8, -10, and -12 in the theca layer and GAL-1, - 8, -10, and -12 in the granulosa layer was identified in white and yellow follicles. The expression of these genes was not changed in the theca and granulosa layers during follicular growth except for a decrease in that of GAL-1 in theca. The expression of GAL-1, -7, and -12 in the theca layer of the third largest follicles was increased in response to LPS at a dose of 1 mg/kg body weight and this increase was induced within 3 h and maintained until 12h postinjection. Granulosa layers did not respond to LPS until 12h injection. These results show that six and four types of GALs are expressed in the theca and granulosa layers of healthy follicles respectively, and their levels do not change with follicular growth except for GAL-1 in theca. Elevated levels of GAL-1, -7, and -12 expression in theca in response to LPS suggest that the theca cells expressing these GALs function to eliminate LPS-containing bacteria.  相似文献   
49.
This paper presents experimental data measured in a bed of gypsum boards in the transient moisture transfer (TMT) facility at the University of Saskatchewan. The relative humidity and temperature were measured at two depths in a gypsum bed and the moisture accumulation was measured for the entire bed. Experiments were conducted for both coated (acrylic and latex paint) and uncoated gypsum. These experimental data are compared to simulated data from eight different numerical models. The agreement between the experimental and numerical data is good and often within the experimental uncertainty bounds. A sensitivity analysis was performed to show the influence of material properties such as sorption, vapour permeability and the transfer coefficients on the simulated results. One model examines hysteresis of the sorption isotherm.  相似文献   
50.
Different ways of implementing dimension-by-dimension CWENO reconstruction are discussed and the most efficient method is applied to develop a fourth order accurate finite volume central scheme for multi-dimensional hyperbolic problems. Fourth order accuracy and shock capturing nature of the scheme are demonstrated in various nonlinear multi-dimensional problems. In order to show the overall performance of the present central scheme numerical errors and non-oscillatory behavior are compared with existing multi-dimensional CWENO based central schemes for various multi-dimensional problems. Moreover, the benefits of the present fourth order central scheme over third order implementation are shown by comparing the numerical dissipation and computational cost between the two.  相似文献   
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